Abstract
The novel hydroxo-bridged dimeric lead-chromium carbonyl complex [Et 4N]2[{PbCr2(CO)10} 2(μ-OH)2] ([Et4N]2[1]) was synthesized from the reaction of PbCl2 and Cr(CO)6 followed by metathesis with [Et4N]Br in a KOH/MeOH solution. The X-ray crystallographic structure shows that dianion 1 consists of two Pb{Cr(CO)5}2 units bridged by two hydroxo fragments in which the Pb atoms are further coordinated with two Cr(CO)5 groups, resulting in a distorted tetrahedral geometry. A CO2 molecule can insert itself into dianion 1 to form two new carbonate complexes, [Et 4N]2[{PbCr2(CO)10}(CO3)] ([Et4N]2[2]) and [Et4N]2[{PbCr 2(CO)10}2(CO3)] ([Et 4N]2[3]), depending on the reaction conditions. In addition, complex 2 can be transformed into 3 in CH2Cl2 solution at an elevated temperature. While the carbonate group in dianion 2 is bonded to one Pb atom, which is coordinated with two Cr(CO)5 fragments, the carbonate group in 3 bridges the two Pb centers in a μ-1κ2OO′:2κ2OO′ fashion in which each Pb atom is further bonded to two Cr(CO)5 moieties. Complexes 2 and 3 can be converted back the hydroxo complex 1 under appropriate conditions. All three unprecedented lead-chromium compounds, 1-3, were fully characterized by spectroscopic methods and single-crystal X-ray diffraction analyses. The nature and formation of complexes 1-3 were also examined by molecular orbital calculations using the B3LYP method of the density functional theory.
Original language | English |
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Pages (from-to) | 6740-6747 |
Number of pages | 8 |
Journal | Inorganic Chemistry |
Volume | 45 |
Issue number | 17 |
DOIs | |
Publication status | Published - 2006 Aug 21 |
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry